1. Field of the Invention
The present invention relates to a biosensor.
2. Related Background Art
“Biosensor” is a general term for chemical sensors that utilize biological molecular recognition mechanisms, and known types of biosensors include enzyme sensors, immunosensors, microbiological sensors, ion channel sensors and the like.
Biosensors accomplish detection of analytes by converting a change (for example, a substance change, color change, heat absorption or release, mass change or the like) produced-by interaction between an enzyme, antibody, microbe, ion channel or the like that is immobilized on a substrate recognition element, and its substrate (the analyte), into a signal that is detectable using a signal converter (an electrode, light receiving element, thermal element, piezoelectric element, fluorescent anisotropy detector or the like).
For example, in a construction where a monoclonal antibody is immobilized on the substrate recognition element and an antigen (the analyte) is allowed to specifically bind with the monoclonal antibody by antigen-antibody reaction, the sensor can obtain a signal proportional to the concentration of the analyte even when contaminants are abundant in the sample.
The lactic acid producing bacterium Mutans Streptococci is associated with intraoral caries. It has therefore been proposed that onset of caries can be prevented by detecting the major Mutans Streptococci bacterium detected in the human mouth, Streptococcus mutans, by antibody immunoassay (Patent document 1).
Since Streptococcus mutans is known to secrete glucosyltransferase in the mouth, the use of an antibody that specifically binds this enzyme for immunological detection of the bacterium has also been proposed (Patent document 2).    [Patent document 1] Japanese Unexamined Patent Publication No. 2003-183299    [Patent document 2] Japanese Unexamined Patent Publication No. 2002-267673